Research On Dynamic Traffic Assignment Theory Considering Air Pollutant Emission Control

With the conviction that lucid waters and lush mountains are invaluable assets,an establishment of sustainable society has become the national strategy.Traffic pollution is one the important sources of atmospheric pollution,which is closely related to environmental quality.The harmonious development of urban transportation and environment has become an imporation issue that cannot be avoided in various regions.Residents are paying more and more attention to the environment and health,not only the travel costs,but the time,comfort and environmental factors.The study about the dynamic traffic assignment considering the control of pollutant emission control can provide some theoretical support for the greesn transportation.It has stong theretical value and practical value.Based on the portable emission measurement system,emission data of kinds of vehicles about were collected on different types of roads and the surroundings.Through the literature review and consultation from the relevant department,the relationship betwee the pollutants concentration and health effects were studied.The extra health loss caused by pollutants was estimated based on the real-world data.The mathematical models were established and optimized in the field of dynamic traffic assignment.The relationship between the concentration of atmospheric pollutants and the incidence of disease was used,and the relationship between the relative risk of pollutants and the excess disease rate was established.Based on the theory of atmospheric environmental capacity and the theory of traffic flow,a definition of health-based environmental traffic capacity based on health loss and ambient air quality standards was proposed.The relationship between the source strength of the road section and the traffic flow was established.Under the pollutant dispersion model,a model based on pollutant inhalation factor,environmental quality limit and physical capacity was established.The inhalation factor of pollutants indicates that when the traffic flow of motor vehicles is low,the inhalation factor of walkers and non-motorized travellers accounts for more than 60%.Environmental traffic capacity is not only affected by the traffic volume of motor vehicles,but also by the traffic flow structure.The source of the driving and idling line are used to jointly analyze the concentration of pollutants in the vicinity of intersection.The environmental traffic capacity of the intersection is determined by the environmental quality standards,the ideal traffic capacity,the delay level and the inhalation factor.The environmental traffic capacity at the signalized intersection is affected by the type of pollutants selected and the inhalation factor.It is discussed that when the health-based environment traffic capacity is equal to the actual physical road traffic capacity,the dynamic user equlibrium in dynamic traffic assignment only needs to consider the travel time impedance.When the health-based environment traffic capacity is smaller than the actual physical capacity,then travellers need to consider impedance with health loss to select a path.Finally,relying on the road network,a case study was given to prove that the model has good applicability,which can provide support for the actual traffic control managenment and dynamic traffic assignment theory research.